Developmental transformation of dendritic arbors in mouse whisker thalamus

Neurons in slices though the somatosensory thalamus of postnatal day 6 and adult mice were injected with Lucifer yellow. Dendritic arbors on postnatal day 6 are confined to single barreloids (single whisker representations); in adults they are seven times longer, extending beyond their barreloid to adjacent barreloids. The postnatal transformation of dendritic arbors by total process growth and extension to adjacent barreloids suggests a developmental change in the role of these cells from instructing whisker pattern formation to integrating sensory information from more than one whisker.